UNIVERSITY  OF  CALIFORNIA  Agricultural  Experiment  Station 

COLLEGE   OF  AGRICULTURE  E.  J.  Wickson,  director 

BERKELEY,   CALIFORNIA 


CIRCULAR  No.  35 

(February,  1908.) 


SOUTHERN  CALIFORNIA  PATHOLOGICAL  LABORATORY 
AND  CITRUS  EXPERIMENT  STATION. 


BY 

EALPH  E.  SMITH. 


The  following  law  was  enacted  by  the  California  Legislature  of  1905 : 

Statutes  and  Amendments  to  the   Code. 

Chapter  CCLXXVIIL 

An  Act  providing  for  the  establishment  and  maintenance  of  a  pathological 
laboratory  for  the  investigation  of  tree  and  plant  diseases  and  pests,  and 
branch  agricultural  experiment  station,  and  making  an  appropriation  therefor. 

The  people  of  the  State  of  California  represented  in  Senate  and  Assembly, 
do  enact  as  follows: 

Section  I.  There  shall  be  established  at  a  point  and  by  means  hereinafter 
provided  a  scientific  station  or  laboratory  with  the  necessary  grounds  and  build- 
ings; this  laboratory  shall  be  equipped  with  the  material  and  appliances  neces- 
sary for  the  study  and  determination  of  the  cause  of  diseases  and  conditions 
of  orchard  trees,  fruits  and  vegetables  and  shall  provide  the  means  for  a 
thorough  examination  of  fungus,  bacterial,  and  other  maladies,  insects,  pests, 
and  diseases,  and  their  remedy  or  prevention,  the  condition  of  the  soil,  cultiva- 
tion and  location  that  may  tend  to  the  imperfect  nutrition  and  all  physiological 
and  other  defects  that  may  affect  the  economic  production  and  marketing  of 
horticultural  products. 

Sec.  2.  The  location  of  such  pathological  laboratory  shall  be  in  one  of 
the  seven  southern  counties  of  the  State  of  California,  to  be  selected  by  a  board 
of  three  commissioners  hereby  created,  consisting  of  the  governor  of  the  State, 
the  president  of  the  University  of  California  and  the  professor  of  agricultural 
practice  of  the  University  of  California,  and  said  board  of  commissioners  is  hereby 
authorized  and  empowered  to  select  such  location,  perfect  the  title  thereof  in  the 
name  of  the  board  of  regents  of  the  University  of  California  and  do  such  other 
acts  as  may  be  necessary  to  make  legal  the  expenditure  of  the  funds  required  by 


the  purpose  of  this  act;  provided  that  said  location  may,  at  the  option  of  the  board 
of  commissioners,  be  on  lands  already  belonging  to  the  State  of  California  at 
Whittier  or  Patton. 

Sec.  3.  When  the  title  to  the  necessary  lands  has  been  perfected  by 
the  commission  named  in  section  two  the  regents  of  the  University  of  California 
shall  proceed  to  the  construction  of  a  building  suitable  for  the  protection  and 
use  of  the  laboratory,  shall  equip  the  laboratory  and  maintain  it  for  the  purposes 
designated  in  the  title  of  this  act,  and  may  receive,  manage,  use,  and  hold  gifts, 
leases,  and  bequests  for  promoting  the  purposes  of  this  act. 

Sec.  4.  The  board  of  regents  or  the  president  of  the  University  of  Cali- 
fornia, if  the  regents  so  authorize,  shall  select  not  less  than  two  experts  in  plant 
pathology,  and  such  assistants  as  may  be  needed,  who  shall  have  active  charge 
oi'  the  laboratory  and  the  investigations  and  field  experiments,  and  who  shall 
reside  at  or  near  the  said  laboratory  and  give  their  entire  time  to  the  investiga- 
tions required  by  the  board  of  regents  or  their  representative,  and  may  from 
time  to  time  publish  the  results  of  their  inquiries  and  discoveries;  the  said 
board  of  regents  shall  fix  the  salaries  of  employes  and  provide  for  contingent 
expenses. 

Sec.  5.  Said  commissioners  shall  also  establish  and  maintain  a  branch  agri- 
cultural experiment  station  or  stations  under  the  provisions  of  this  act  within 
the  territory  described  in  section  two  of  this  act  for  the  purpose  of  carrying 
on  experimental  and  investigational  work  in  connection  with  the  agricultural 
experiment  work  of  the  University  of  California  in  ascertaining  the  best 
methods  of  horticultural  management;  for  the  investigation  of  fertilization; 
for  the  investigation  of  irrigation;  for  improving  the  methods  of  handling 
fruits  for  market;  for  the  introduction  of  new  varieties  of  fruits  and  for  such 
other  investigations  as  may  be  deemed  advisable  to  promote  the  horticultural  inter- 
ests of  said  district.  Said  commissioners  may  lease  or  accept  gifts  of  lands  for 
said  purpose  and  may  select  for  the  location  of  said  station  or  stations  any  lands 
owned  by  the  state  in  said  district;  provided  that  should  such  station  or  stations 
be  located  upon  lands  owned  by  the  state  at  the  Whittier  Kef  orm  School  at  Whittier 
or  the  Southern  California  State  Hospital  at  Patton  they  shall  not  embrace  in  the 
aggregate  more  than  fifty  acres.  Said  land  shall  be  supplied  wtih  sufficient  water 
for  the  proper  irrigation  of  the  same  in  any  case. 

Sec.  6.  The  regents  of  the  University  of  California  are  required  to  adopt 
a  general  plan  and  schedule  before  the  beginning  of  each  fiscal  year  which  shall 
describe  the  investigations  and  experiments  to  be  pursued  during  such  fiscal 
year,  and  it  shall  be  the  duty  of  the  board  of  regents  to  receive  and  consider 
written  statements  from  individuals  and  associations  interested  in  said  branches 
of  horticulture,  conveying  plans  and  suggestions  for  investigations  which  they 
may  approve  or  desire. 

Sec.  7.  The  sum  of  thirty  thousand  dollars  is  hereby  appropriated  out  of 
any  money  in  the  state  treasury  not  otherwise  appropriated  to  be  expended  by 
the  regents  of  the  University  of  California  in  carrying  out  the  purposes  of  this 
act,  and  the  state  controller  is  hereby  authorized  and  directed  to  draw  his  war- 
rant for  the  same  payable  to  the  regents  of  the  University  of  California,  and  the 
treasurer  of  the  state  is  hereby  directed  to  pay  such  warrants. 


This  rather  indefinite  measure  had  its  origin  in  two  distinct  move- 
ments which  had  been  gaining  ground  in  southern  California  for  some 
time.  One  was  a  growing  realization  of  the  need  of  some  local  insti- 
tution to  provide  for  the  investigation  of  plant  diseases,  as  distinct 
from  insect  pests.  The  increasing  prevalence  of  troubles  of  this  sort, 
fungus,  bacterial,  or  of  unknown  nature,  and  the  almost  entire  lack  of 
definite  knowledge  concerning  them,  made  most  desirable  the  establish- 
ment of  some  agency  for  furnishing  information  along  these  lines. 
This  demand  was  most  active  in  the  coastward  regions  where  crop 
production  is  more  varied  and  plant  diseases  more  prevalent  than 
farther  inland. 

Another,  quite  distinct  movement,  originated  in  a  feeling  among 
citrus  growers  of  the  necessity  of  scientific  investigation  in  connection 
with  the  various  phases  of  citrus  culture.  In  the  use  of  fertilizers, 
improvement  of  varieties,  methods  of  irrigation  and  cultivation,  study 
of  soil  problems,  and  many  other  matters,  the  most  foresighted  growers 
foresaw  the  need  of  a  deeper  source  of  information  than  their  own 
practical  experience. 

Regarding  the  work  of  the  State  Agricultural  Experiment  Station, 
at  Berkeley,  which  had  been  by  no  means  inactive  along  these  lines,  it 
was  felt  that  the  Station  was  too  far  away  for  the  most  effective,  in- 
tensive work,  and  the  State  too  large  for  southern  California  and  its 
industries  to  receive  sufficient  attention  through  ordinary  channels. 
Hence  came  about,  by  chance  simultaneously,  these  two  efforts  to  pro- 
vide local  branches  of  the  Station  for  special  work.  Two  distinct  bills 
were  first  introduced  in  the  Legislature,  which,  from  their  somewhat 
similar  nature,  were  combined  into  one,  providing  literally  for  at  least 
two  separate  institutions  for  the  purposes  specified. 

The  members  of  the  Commission  designated  to  locate  and  establish 
the  "  Pathological  Laboratory  and  Branch  Experiment  Station  or 
Stations,"  after  several  visits  to  southern  California  and  inspection 
of  a  number  of  sites  offered  for  the  purpose,  decided  on  the  organi- 
zation of  a  single  institution,  with  two  localized  branches :  a  patholog- 
ical laboratory  at  Whittier  and  a  citrus  experiment  station  at  Riverside. 
This  segregation  was  determined  on  for  the  convenience  of  the  work, 
and  coincided  with  the  conditions  which  prompted  the  original  move- 
ment. 

Near  the  coast  are  located  the  principal  sections  of  walnuts,  vege- 
tables, berries,  lemons,  and  other  products  most  threatened  with  various 
diseases,  and  diseases  of  the  same  crop  are  more  prevalent  here  than 
in  the  interior.    In  the  latter  section  is  the  greatest  citrus  belt,  center- 


ing  at  Riverside,  and  here  is  the  logical  home  of  any  purely  citrus 
institution.  Under  a  single  management  and  control  it  seemed  that 
the  work  could  be  made  most  effective  under  this  organization. 

The  Pathological  Laboratory. 

The  site  selected  for  this  branch  consists  of  about  an  acre  of  land 
in  the  city  of  Whittier,  at  the  corner  of  Greenleaf  avenue  and  Baldwin 
street,  one  block  beyond  the  terminus  of  the  Pacific  Electric  Company's 


f»£ 


Fig.   1. — Southern  California  Pathological  Laboratory  at  Whittier. 


trolley  line  from  Los  Angeles.  This  location  is  easily  accessible  from 
all  points  and  in  a  center  of  walnut,  lemon,  vegetable,  and  berry  pro- 
duction. The  site  was  donated  by  the  Whittier  Board  of  Trade  through 
local  subscription.  Beside  the  acre  of  ground  belonging  to  the  labor- 
atory, land  is  available  for  more  extensive  plantings  on  the  large  farm 
of  the  Whittier  State  School,  a  State  institution  close  by. 

A  laboratory  building  has  just  been  completed  at  Whittier.  This 
consists  of  a  two-story,  frame  building  of  very  substantial  construction, 
40  X  50  feet,  with  a  shed  and  green-house  annexed.  On  the  lower  floor 
are  located  the  general  office,  15  X  20  feet,  library,  private  office  and 
laboratory,  culture  storage  room,  chemical  and  sterilizing  laboratory, 


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Fig.  2. — First  floor,  Pathological  Laboratory  at  Whittiei 


and  a  general  laboratory,  15  X  30  feet.  The  second  floor  contains  a 
museum,  photographic  room,  entomologist's  office  and  laboratory,  pri- 
vate laboratory,  and  janitor's  room.  The  building  has  gas,  water,  and 
electricity  throughout,  and  is  well  equipped  with  furniture,  benches 
and  cases,  microscopic  and  culture  apparatus,  glassware  and  supplies. 
It  is  in  every  respect  a  first-class,  practical,  up-to-date  laboratory  for 
its  purpose.  The  green-house  consists  of  three  compartments  with 
double  glass  walls  and  air  space  between,  and  is  intended  for  experi- 
mental purposes. 


Fig:  3. — Second  floor,   Pathological  Laboratory  at  Whittier 


The  intention  is  to  make  the  Whittier  laboratory  a  headquarters  of 
investigation  in  plant  pathology,  including  entomology,  for  southern 
California.  The  study  of  the  various  diseases  and  troubles  affecting 
cultivated  plants  will  receive  concentrated  attention,  both  from  a  tech- 
nical and  practical  standpoint.  Collections,  museum  material,  etc., 
will  be  prepared  and  the  laboratory  will  be  made  an  object  of  attraction 
from  a  botanical  and  horticultural  standpoint,  representing  one  of  the 
most  important  extensions  of  the  agricultural  work  of  the  University 
of  California. 

Opportunities  are  offered  for  a  limited  number  of  properly  pre- 
pared graduate  or  advanced  students  to  avail  themselves  of  the  facil- 
ities of  the  laboratory  for  research,  either  as  candidates  for  a  degree  or 
not.  Such  students  will  be  governed  by  the  usual  regulations  of  the 
University  of  California,  concerning  which  information  can  be  obtained 
from  the  Recorder  of  the  Faculties,  Berkeley.  The  laboratory  location 
is  practically  frostless,  affording  an  agreeable  climate  and  outdoor 
growth  of  most  plants  with  slight  protection  all  the  year  round.  Local 
pioblems  abound  in  plant  pathology  and  entomology,  and  the  condi- 
tions are  unexcelled  for  cultural,  life  history,  histological,  ecological 
and  other  studies. 

The  present  work  of  the  laboratory  is  centered  largely  on  problems 
connected  with  walnut,  citrus,  and  vegetable  growing.  Perhaps  the 
most  important  subject  is  that  of  the  walnut  blight,  the  serious  bacte- 
rial disease  affecting  the  English  walnut.  A  large  amount  of  work 
has  been  and  is  being  done  upon  this  subject.  The  most  important 
results  to  date  have  been  the  demonstration  of  the  necessity  and  the 
practical  value  of  better  cultural  operations  in  walnut  production. 
The  industry  has  grown  up  rapidly,  with  little  attention  to  systematic 
or  intensive  methods  of  culture.  The  present  bearing  orchards  are 
almost  all  of  seedling  trees,  of  very  diverse  character  and  quality. 
Soil  fertilization  is  unknown,  irrigation  practice  has  no  system  or 
standards,  and  cultivation  is  for  the  most  part  superficial  and  little 
practiced.  Under  such  conditions  the  blight  has  caused  much  loss,  yet 
its  effects  are  far  less  than  those  commonly  ascribed  to  it.  The  almost 
entire  lack  of  good  cultural  practice,  now  that  the  earlier  planted 
groves  are  getting  older,  is  having  an  even  more  serious  effect. 

The  only  possible  direct  treatment  for  blight  control  appears  to  be 
in  the  line  of  spraying.  After  considerable  work  in  this  direction  by 
the  Pathological  Laboratory,  as  well  as  by  a  number  of  growers,  it 
appears  extremely  doubtful  whether  any  treatment  of  this  sort  can 
ever  be  made  a  practical  success.    Regardless  of  the  effect  on  the  dis- 


8 

case,  the  expense  and  difficulty  of  thorough  spraying  on  mature  walnut 
trees  is  so  great  as  to  render  the  general  adoption  of  any  possible 
treatment  of  this  sort  extremely  doubtful. 

The  greatest  effort  at  present  is  therefore  being  made  along  the 
line  of  improved  cultural  methods  and  trees  of  better  quality,  in  which 
direction  there  is  much  promise  of  fairly  quick  results.  As  regards 
the  tree  itself  it  has  already  been  demonstrated  that  there  are  varieties 
or  certain  individual  trees  which  are  much  less  affected  by  the  disease 
than  the  average  seedlings.  In  the  same  connection  it  is  necessary 
that  the  quality  and  productive  powers  of  such  nuts  be  demonstrated, 
as  well  as  their  blight  resistance.  For  this  purpose  an  experimental 
walnut  orchard  has  been  started  by  the  laboratory,  in  which  are  being 
grown  all  obtainable  varieties  and  selected  trees.  This  planting  will 
be  most  valuable  in  demonstrating  the  behavior  of  the  various  kinds 
under  local  conditions.  So  far  as  possible  trees  of  each  variety  are 
planted  on  a  variety  of  root  stocks,  California  Black,  Eastern  Black, 
English,  etc.,  while  at  the  same  time  all  these  stocks  are  being  grown 
from  seed  for  experimental  plantings.  This  work  tends,  naturally,  to 
have  its  value  mostly  for  future  plantings.  The  problem  of  regener- 
ation of  present  orchards  is  of  no  less  importance.  With  this  in  mind 
the  possibilities  of  top  grafting  old  trees  into  better  kinds  are  being 
looked  into  and  demonstrated  with  considerable  promise  of  good  results. 

The  excellent  results  of  better  fertilization,  irrigation,  and  culti- 
vation in  walnut  orchards,  as  largely  increasing  the  yield  in  spite  of 
the  disease,  are  rapidly  coming  to  the  front.  An  important  extension 
of  the  work  of  the  Pathological  Laboratory  in  this  field  has  been  made 
possible  by  an  arrangement  with  the  Cudahy  Ranch,  near  Los  Angeles, 
through  Superintendent  John  Hund.  The  large  acreage  of  walnuts 
on  this  ranch  and  liberal  attitude  of  the  owner  has  permitted  the  laying 
out  and  carrying  on  of  fertilizer  and  irrigation  experiments  on  a  scale 
and  over  a  series  of  years  which  would  be  impossible  with  an  ordinary 
grower.  This  work  should  begin  to  show  important  results  in  the  near 
future.  Similar  experiments  on  a  smaller  scale  are  being  carried  on 
with  other  groves. 

The  diseases  of  citrus  trees  form  an  important  subject  of  investi- 
gation at  the  Pathological  Laboratory  and  will  soon  become  the  subject 
of  publications. 

Diseases  of  tomatoes,  asparagus,  and  other  vegetables  are  receiving 
attention  in  the  field  and  laboratory,  along  with  many  other  miscella- 
neous matters. 


Citrus  Experiment  Station. 

This  branch  of  the  work  is  located  at  Riverside,  one  mile  west  of 
the  city,  at  the  east  base  of  Rubidoux  Mountain,  on  land  furnished  by 
the  Huntington  Park  Association  of  that  place.  With  the  original 
property  and  subsequent  leases  there  are  now  about  30  acres,  mostly 
excellent  citrus  land,  under  the  Station  control.    The  present  buildings 


Fig.  4. — Citrus  Experiment  Station  at  Riverside. 


comprise  two  cottages  and  a  small  stable  which  were  on  the  original 
property,  and  a  new  work  shop  and  stable  just  built.  A  general  lab- 
oratory and  office  building  will  soon  be  needed.  A  large  reservoir  has 
been  built  at  the  upper  end  of  the  property,  an  electric  pump  installed 
on  the  pipe  line  which  runs  across  the  ground,  and  flumes,  pipes,  out- 
lets, catch  basins,  etc.,  put  in  for  a  complete  irrigation  system. 

The  purpose  of  the  Citrus  Experiment  Station,  as  conceived  by  its 
management,  is  to  provide  for  the  State  Agricultural  Experiment 
Station  adequate  facilities  for  the  investigation  of  all  subjects  having 
important  bearing  on  citrus  production.  For  this  purpose,  as  with 
the  pathological  laboratory,  local   initiative  is  necessary.     The   most 


10 

important  problems  of  the  citrus  industry  at  present  lie  in  the  direction 
of  the  cultural  and  pomological  considerations  which  have  to  do  with 
the  production  and  quality  of  the  fruit.  To  such  problems  the  Station 
is  therefore  preparing  to  give  attention. 

The  necessity  of  soil  fertilization  in  citrus  orchards  has  brought 
about  an  extensive  use  of  fertilizing  elements,  but  with  little  definite 
knowledge  of  specific  requirements  or  effects.  This  is  perhaps  the 
most  important  cultural  problem  to-day  in  California  citrus  culture. 
Particularly  lacking  is  information  as  to  the  specific  effects  of  the 
essential  elements  and  most  common  sources  of  fertility  on  the  quality 
of  the  fruit.  Little  more  is  practiced  at  present  than  the  liberal  use 
of  complete  fertilizer  or  its  equivalent,  stable  manure,  and  nitrogen. 
To  establish  a  foundation  for  the  desired  information,  an  eight-acre 
planting  has  been  made  at  the  Station,  comprising  20  similar  plots 
each  containing  Washington  Navel  and  Valencia  oranges,  Lisbon  and 
Eureka  lemons,  with  the  necessary  check  rows  between  plots.  An 
irrigation  system  has  been  put  in  by  which  each  plot  can  be  watered 
separately,  and  all  waste  or  rain  water  carried  off  without  running 
from  one  plot  to  another.  These  20  plots  have  been  fertilized  as  fol- 
lows, and  will  continue  indefinitely  with  the  application  of  the  same 
substance  each  year:  Plot  1,  Nitrate  of  Soda  (Inorganic  Nitrogen). 
Plot  2,  Dried  Blood  (Organic  Nitrogen).  Plot  3,  Sulfate  of  Potash. 
Plot  4,  Muriate  of  Potash.  Plot  5,  Rock  Superphosphate.  Plot  6, 
Bone  Superphosphate.  Plot  7,  Raw  Bone.  Plot  8,  Manure.  Plot  9, 
Nitrate  of  Soda,  Dried  Blood,  Superphosphate,  Sulfate  of  Potash 
(complete).  Plot  10,  Nitrogen  and  Phosphoric  Acid  (no  Potash). 
Plot  11,  Nitrogen  and  Potash  (no  Phosphoric  Acid).  Plot  12,  Phos- 
phoric Acid  and  Potash  (no  Nitrogen).  Plots  13,  14,  15,  16,  and  17, 
are  duplicates  of  2,  3,  5,  8,  and  9.  Plots  18,  19,  and  20  are  Checks,  no 
fertilizer.  As  these  trees  develop  to  bearing  age,  with  the  treatment 
indicated,  it  is  believed  that  an  object  lesson  will  be  afforded  which 
will  do  much  toward  establishing  a  firmer  basis  of  knowledge  of  the 
specific  effects  of  fertilizing  elements  on  citrus  trees.  For  experiments 
of  the  same  sort  on  trees  of  producing  age  a  10-acre  block  of  trees 
adjoining  the  Station  has  been  leased,  and  will  be  devoted  to  this  and 
other  experimental  purposes,  particularly  in  relation  to  the  nature, 
amount,  and  time  of  application  of  fertilizers.  The  fact  is  fully  real- 
ized that  results  of  such  experiments  at  the  Station  on  one  type  of  soil 
cannot  be  applied  indiscriminately  on  all  soils  or  in  all  localities.  The 
idea  is  rather  to  demonstrate  basic  principles  in  this  manner,  which 
may  then  serve  as  a  foundation  for  other  field  trials  on  a  commercial 


11 

basis  and  in  various  places,  in  cooperation  with  growers.  The  whole 
matter  of  fertilizer  requirements  and  practice,  and  soil  composition, 
structure  and  treatment  must  ultimately  receive  from  the  Station 
highly  specialized  investigations  to  keep  pace  with  modern  progress  of 
knowledge,  continuing  and  extending  the  previous  investigations  in 
this  field  of  Professor  Hilgard  and  his  associates  of  the  State  Experi- 
ment Station. 

The  character  of  the  tree  itself  used  in  planting  a  citrus  orchard  is 
of  the  greatest  importance,  and  investigations  along  this  line  are  being 
undertaken.  As  regards  the  kind  of* root,  plantings  have  been  made 
of  the  varieties  above  mentioned,  each  on  various  root  stocks  and  on 
light  and  heavy  soil.  Seed  beds  have  also  been  started  of  the  various 
species,  sweet  orange,  sour  orange,  pomelo,  and  Citrus  trifoliata.  The 
value  of  seed  from  selected  trees  is  also  being  tested.  Concerning  the 
top  of  the  tree  a  special  effort  has  been  commenced  for  the  improve- 
ment of  present  varieties  by  bud  selection  from  trees  of  certain  pecu- 
liarities. A  considerable  number  and  variety  of  buds  have  been  secured 
during  the  present  season,  and  propagated  in  nursery  stock.  A  col- 
lection of  citrus  species  and  varieties  has  also  been  started  on  the 
Station  grounds. 

In  general  the  Citrus  Experiment  Station  will  be  made  a  center  of 
investigations  relating  to  the  culture  of  citrus  trees.  Its  activities  will 
by  no  means  be  confined  to  experiments  on  the  Station  grounds  proper, 
but  will  comprise  broad  investigations  of  specific  problems  as  related 
to  the  citrus  industry. 


